Led light engine

ABSTRACT

An integrated Light Emitting Diode (LED) device including multiple LEDs connected to a circuit board, integrated circuit (IC) drivers connected to the circuit board, and a first alternating current (AC) terminal and a second AC terminal connected to the circuit board.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/189,648, filed Aug. 21, 2008, and U.S. Provisional Application No.61/095,250, filed Sep. 8, 2008, all of which are incorporated herein byreference.

BACKGROUND

1. Field of the Invention

The present invention relates generally to Light Emitting Diode (LED)lighting, more particularly, to LED light engines.

2. Description of the Related Art

For solid state lighting, there are three main components of a luminary:LEDs, the driving circuitry, and the housing. In most cases, a designerwould have to select LEDs, come up with driving circuitry, and designthe circuit board for placing the assembly.

There are very few offerings of LED modules for lighting designers tojust integrate into a housing to see if it fits the intendedapplication. Of the few LED modules, they still require external drivingcircuitry. An issue with using direct Alternating Current (AC) is thatthe total harmonic distortion of current (THDi) is high. Most energyprograms require total THDi to be lower than 20% to qualify.

BRIEF SUMMARY

One aspect of an embodiment of the invention includes an integratedLight Emitting Diode (LED) device including multiple LEDs connected to acircuit board, integrated circuit (IC) drivers connected to the circuitboard, and a first alternating current (AC) terminal and a second ACterminal connected to the circuit board.

Another aspect of an embodiment of the invention provides an LED systemcomprising a plurality of integrated circuit (IC) boards coupled to oneanother, each of the plurality of IC boards comprising: a plurality ofLEDs coupled to each IC board, a plurality of LED IC drivers coupled toeach IC board, and a first pair of alternating current (AC) terminalsand a second pair of AC terminals coupled to each IC board. A secondpair of AC terminals of a first IC board couples with a first pair of ACterminals of a second IC board.

Yet another aspect of an embodiment of the invention provides an LEDdriving method comprising: providing a circuit board, integrating aplurality of LEDs to the circuit board, integrating a plurality of LEDintegrated circuit (IC) driver circuits with the circuit board, wirebonding the LEDs and the LED IC driver circuits, and coupling thecircuit board to an AC line voltage source.

Other aspects and advantages of the present invention will becomeapparent from the following detailed description, which, when taken inconjunction with the drawings, illustrate by way of example theprinciples of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For a fuller understanding of the nature and advantages of theinvention, as well as a preferred mode of use, reference should be madeto the following detailed description read in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates a customizable chip-on-board (COB) Light EmittingDiode (LED) and a driver module(s) according to one embodiment of theinvention;

FIG. 2 illustrates a system of customizable COB LED and driver modulesaccording to one embodiment of the invention;

FIG. 3 illustrates a block diagram of a process according to oneembodiment of the invention;

FIG. 4 illustrates a customizable COB LED, driver modules and a totalharmonic distortion of current (THDi) circuit according to anotherembodiment of the invention; and

FIG. 5 illustrates a customizable COB LED, driver modules and a dimmingcircuit according to still another embodiment of the invention.

DETAILED DESCRIPTION

The following description is made for the purpose of illustrating thegeneral principles of the invention and is not meant to limit theinventive concepts claimed herein. Further, particular featuresdescribed herein can be used in combination with other describedfeatures in each of the various possible combinations and permutations.Unless otherwise specifically defined herein, all terms are to be giventheir broadest possible interpretation including meanings implied fromthe specification as well as meanings understood by those skilled in theart and/or as defined in dictionaries, treatises, etc. The descriptionmay disclose several preferred embodiments for Light Emitting Diode(LED) chip-on-board (COB) and driver integrated circuit modules,devices, and methods, as well as operation and/or component partsthereof. While the following description will be described in terms ofintegrated LED light driver integrated circuit devices, systems andmethods for clarity and placing the invention in context, it should bekept in mind that the teachings herein may have broad application to alltypes of systems, devices and applications.

One embodiment of the invention includes an integrated Light EmittingDiode (LED) device including multiple LEDs connected to a circuit board,integrated circuit (IC) drivers connected to the circuit board, and afirst alternating current (AC) terminal and a second AC terminalconnected to the circuit board.

FIG. 1 illustrates an embodiment of the invention including anintegrated LED driver circuit 100. In one embodiment of the invention,the LED driver circuit 100 may be assembled as a COB or discretepackaged components. In one embodiment of the invention, the integratedLED driver circuit 100 includes a circuit board 110, LED IC drivers 120,first AC terminals 130, second AC terminals 140, LEDs 150, andprotection diodes 160. In one embodiment of the invention, the LEDs areassembled as COB. The AC terminals 130 and 140 are configured to connectto an AC line voltage of 120V.

In one embodiment of the invention, the circuit board 110 is a metalcore circuit board. In some embodiments of the invention, the LED ICdrivers 120, first AC terminals 130, second AC terminals 140, LEDs 150,and protection diodes 160 are wire bonded without the use of pads ortraces. In this embodiment of the invention, the circuit board 110 isdirectly connected to an AC line voltage such as 120 VAC without anexternal power supply.

In one embodiment of the invention, the plurality of LEDs 150 aretreated with phosphor deposition and encapsulated. In this embodiment ofthe invention, the phosphor deposition treats blue LEDs to yield whitelights.

In one embodiment of the invention, the integrated LED driver circuit100 further includes at least one total harmonic distortion of current(THDi) circuit 410 (see FIG. 4). In this embodiment of the invention,the THDi is maintained under 20%. In another embodiment of theinvention, the integrated LED driver circuit 100 further includes adimming circuit 510 (see FIG. 5). In one embodiment of the invention,the dimming circuit 510 is an IC LED driver circuit including an ENABLEpin for providing brightness control for dimming.

In these embodiments of the invention, combinations including THDicircuit(s) 410 and dimming circuit(s) 510 may also be configured. Someof the embodiments of the invention qualify for energy savings programsknown as “green” programs due to the maintenance of THDi under 20% andalso due to the dimming properties, which also save energy and reducesenergy costs.

In one embodiment of the invention, the LED IC drivers 120 are highvoltage, temperature compensated constant source of current whenconnected to an AC line voltage. In this embodiment of the invention,the LED IC drivers 120 is trimmed to provide a constant current of 20mA±10% at an output voltage of 5.0-90V. In one embodiment of theinvention, the LED IC drivers 120 are connected in parallel to providehigher currents, such as 40 mA, 60 mA or 80 mA. In one embodiment of theinvention, the LED IC driver 120 has a 0.01%/° C. typical temperaturecoefficient and an operating junction temperature of −40° C. to +125° C.

FIG. 2 illustrates a system 200 including multiple integrated LED drivercircuits 100 connected to one another. In this embodiment of theinvention, the die of each LED driver circuits 100 can be placeddirectly next to one another so that light illuminating from theconnected integrated LED driver circuits 100 appears continuous due tothe wire bonding of the LED driver circuits 100.

FIG. 3 illustrates a block diagram of a process 300 for an LED drivingmethod. In block 310, a circuit board is provided, such as circuit board110. In block 320, a plurality of LEDs (e.g., LEDs 150) are integratedto the circuit board. Process 300 continues with block 330 where aplurality of LED integrated circuit (IC) driver circuits are integratedwith the circuit board (e.g., LED IC driver circuits 120). In block 340,the LEDs and the LED IC driver circuits are wire bonded to the circuitboard. Process 300 continues with block 350 where the circuit board isconnected to an AC line voltage source (e.g., 120VAC source).

In one embodiment of the invention, process 300 also includes couplingat least one THDi circuit to the circuit board and coupling at least onedimming circuit to the circuit board. In one embodiment of theinvention, the process 300 provides a THDi of the circuit board lessthan 20%.

In the description above, numerous specific details are set forth.However, it is understood that embodiments of the invention may bepracticed without these specific details. For example, well-knownequivalent components and elements may be substituted in place of thosedescribed herein, and similarly, well-known equivalent techniques may besubstituted in place of the particular techniques disclosed. In otherinstances, well-known structures and techniques have not been shown indetail to avoid obscuring the understanding of this description.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems and methods according to various embodiments of the presentinvention. In this regard, each block in the flowchart or block diagramsmay represent one or more modules, segments, steps, procedures, etc. Itshould also be noted that, in some alternative implementations, thefunctions noted in the block may occur out of the order noted in thefigures. For example, two blocks shown in succession may, in fact, beexecuted substantially concurrently, or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved. It will also be noted that each block of the block diagramsand/or flowchart illustration, and combinations of blocks in the blockdiagrams and/or flowchart illustration, can be implemented by specialpurpose hardware-based systems that perform the specified functions oracts, or combinations of special purpose hardware.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present invention has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the invention. Theembodiment was chosen and described in order to best explain theprinciples of the invention and the practical application, and to enableothers of ordinary skill in the art to understand the invention forvarious embodiments with various modifications as are suited to theparticular use contemplated.

Reference in the specification to “an embodiment,” “one embodiment,”“some embodiments,” or “other embodiments” means that a particularfeature, structure, or characteristic described in connection with theembodiments is included in at least some embodiments, but notnecessarily all embodiments. The various appearances of “an embodiment,”“one embodiment,” or “some embodiments” are not necessarily allreferring to the same embodiments. If the specification states acomponent, feature, structure, or characteristic “may,” “might,” or“could” be included, that particular component, feature, structure, orcharacteristic is not required to be included. If the specification orclaim refers to “a” or “an” element, that does not mean there is onlyone of the element. If the specification or claims refer to “anadditional” element, that does not preclude there being more than one ofthe additional element. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,elements, components, and/or groups thereof.

While certain exemplary embodiments have been described and shown in theaccompanying drawings, it is to be understood that such embodiments aremerely illustrative of and not restrictive on the broad invention, andthat this invention not be limited to the specific constructions andarrangements shown and described, since various other modifications mayoccur to those ordinarily skilled in the art.

1.-22. (canceled)
 23. An integrated Light Emitting Diode (LED) devicecomprising: a plurality of LEDs coupled to a circuit board; a firstalternating current (AC) terminal and a second AC terminal coupled tothe circuit board, the first and second AC terminals connected directlyto a line voltage without an external power supply; one or more constantcurrent sources connected to the first AC terminal and providingconstant current to the plurality of LEDs over a range of voltage; andat least one total harmonic distortion of current (THDi) circuit lessthan 20%.
 24. The integrated LED device of claim 23, further comprisinga dimming circuit.
 25. The integrated LED device of claim 23, whereinthe circuit board is wire bonded.
 26. The integrated LED device of claim23, wherein the plurality of LEDs are treated with phosphor depositionand encapsulated.
 27. The integrated LED device of claim 23, wherein theline voltage is 120V.
 28. The integrated LED device of claim 23, whereinthe plurality of LED IC drivers are temperature compensated.
 29. Theintegrated LED device of claim 23, wherein the circuit board has a metalcore.
 30. A Light Emitting Diode (LED) system comprising: a plurality ofintegrated circuit (IC) boards coupled to one another, each of theplurality of IC boards comprising: a plurality of LEDs coupled to eachIC board; a first pair of alternating current (AC) terminals and asecond pair of AC terminals coupled to each IC board, the first andsecond AC terminals connected directly to a line voltage without anexternal power supply; and, one or more constant current sourcesconnected to the first AC terminal and providing constant current to theplurality of LEDs over a range of voltage, wherein: a second pair of ACterminals of a first IC board couples with a first pair of AC terminalsof a second IC board; each IC board further comprising at least onetotal harmonic distortion of current (THDi) circuit, wherein the LEDsystem is directly coupled to a line voltage without an external powersupply.
 31. The LED system of claim 30, wherein THDi of the system isless than 20%.
 32. The LED system of claim 30, wherein each IC boardfurther comprising at least one dimming circuit.
 33. The LED system ofclaim 30, wherein each IC board is wire bonded.
 34. The LED system ofclaim 30, wherein the plurality of LEDs are treated with phosphordeposition and encapsulated.
 35. The LED system of claim 30, wherein theline voltage is 120V.
 36. The LED system of claim 30, wherein theplurality of LED IC drivers are temperature compensated.